Device for projecting stars



DEVICE FOR PROJECTING STARS Dec. 4, 19.28;

. w. VILLIGER ET AL DEVICE FOR PROJECTING STARS Filed neo. s, 1925 3 sheets-sheet 3 for projecting st-ars, as dealt with in the co-\ Patented Dec. 4, 4192s.

' UNITED STATES l 1,693,969 PATENT OFFICE.

WALTER VILLIGER AND WALTHER BAUERSFELD, OF JENA, GERMANYQ'ASSIGNORS T0 CARL ZEISS (A FIRM), OF JENA, GERMANY.

DEvrcE Fon rRoJEorINssTARs.

Application led December 3, 1925, Serial No. 73,019, and inl Germany December 11, 1924..

rlhe present invention relates to a device pending application Serial No. (368,446, filed October' 13, 1923, Patent No. 1,616,736.

It a device of this kind is to be basedupon a small latitude (in the utmost case the lati'- tude zero), the form represented in the said application does not admit anymore of representing the whole tixed-star sky. `Accord ing to the invention this representa-tion is achieved by disposi-ng the devices for pro-` jecting fixed stars -roundtwo sources of light and by locating them relatively to the latter, and constructing them in such a Way that with the projection the same effect is attained as if the projection would take place from a coininon centre of projection. Thereby the latter need not lie at all events in one of the two sources of light itself. A displacement of the centre of projection may be compensated in a different way,'e. g. by a corresponding arrangement of the stars on the plates to be projected or by altering the inclination of the projection. apparatus or, iinally, by a corre# spending selection of the focal length or' the projection objectives and by a suitable lateral displacement of these objectives. This division ot the devices serving for the projection of thelixed stars also affords the prevention of objectionable castings of shadow of the devices serving for the projection.` of the bodies ot the solar system with the representation of the whole fixed-star sky. These latter devices may henceforth be disposed between the two groups of devices serving for the projection ot fixed stars, so that they lie outside the path of rays of these devices.

In the device represented in the copcnding application it might be possible, as maybe ,easily seen, to achieve a compensation of the rights relatively to the axis of rotation, parallel to the earth axis, only by using special counterpoise. However, according tothe invention such a compensation without counterpoise is attained by an arrangement with which the centre ot gravity of the devices tor projecting the' fixed stars, 'on the one hand, and that of the devices for projecting the bodies -of the solai' systeu'i, on the other hand. lie. outside the said axis ot rotation on ditl'crent sides of it.. Thereby the devices, disposed round a common source of light, for projecting the fixed stars must be located relatively to th'c source of light and constructed in such a Way that the projection seems to take placefrom a centre of projection. which, while lying on the said axis of rotation, isdisplaced relatively tothe source of light.- i

In order to bevv able to adjust any desired inclinations of the earth axis to the horizon, it is advisable to dispose the' carrying appliance, in which the devices for projecting the fixed stars and the bodies of the solar system are supported about an axis parallel to the earth axis, rotatable about a horizontal axis intersecting the said ,former axis of rotation,

and thereby to construct the carrying appliance in such a way as tov render possible rotations of the pedestal body about any desired angles.

In devices for projecting stars itis impossible to use the usual thick-Walled carrying appliances becausein certain positions of the moved parts theywould prevent the light ofv the 'projection apparatus from striking the protection screen4 and thereby cause temporary eclipses of the sta-rs. Hence, only such carrying appliances can be used Whose constructional parts are of small strength perpendicular to the direction of projection (i. e. tangential to the projection screen). It is of particular advantage to onlymake the carrying appliance of stay Wires.

The annexed drawing shows in Figs. 1 to 3 an example of the invention; Fig. l is an elevation, partly in section, Fig.l 2 is a section on the line 2-2 of Fig. 1 and Fig. 3 a sideview. Fig. 45 is a detail of a second example in a section. Figs. 5 and 6 show in an elevation and in plan a second form of the carrying appliance for the device according to 4Figs. 1 to 3. The referenceV letters agree as tar as possible with 'thoseof the copending application.

The device shown in Figs. l to 3 serves for projecting the fixed stars, the sun4 G), the moon (I, and the planets Mercury l, Venus Q ,Mars C? Jupiter 2l and Saturn l2 and for illustrating the motion of these celestial bodies relatively to the earth on the projection screen in such a way as perceived from a certain definite point on the earth. In these figures the mechanisms for producing the motion of the parts requisite for the projeclos tion ofthe celestial bodies G, (t, 9 2,!

and b have, for clearness, beenleft out for the most part and only the appertaining astronomical sign hasbeen inscribed at'the place Where the corresponding mechanisms must be fitted.' The mechanisms may entirely correspond to those shown in the constructional example of the German patent specification 391036, so that it was unnecessaryr to illustrate them in this case.' r

. The new device ditl'ers in the irst place from the one described in the copending ap-- a1 and L2 rotatable about an axis D-Din' such a way that this axis is perpendicular to the axis of rotation X-X and thereby traverses the point of intersection E of the axes of rot-ation Xe-X and Y-Y. The carrying bars al. and a2 are assumed to be suspended with the aid of ropes o1 and o2 within a suitable spherical projection screen in such a way that the point of intersection E lies in the centre of the projection room andthat the axis of rotation D-D is horizontal, whereby other ropes 03 and o4 ensure an invariable position of the carrying bars a1 and a2. By rotating the body n about the axis of rotation D4D it is possible to impart to the axis of rotation X--X, representing the earth axis7 any desired position relatively to the horizontal plane determined by the axis of rotation D"-D, so that any desired latitude willbe adjustable. The latitude-adjusted at any one time is indicated by an index a3 of the pivot n2 on a scale a3 of the carrying bar a2. In the drawing the arrangement has been made in-such a way that the axis of rotation X-X is vertical, hence the device is adjusted according to alatitude of 90. In order to sey cure the latitude chosen, provision is made for a sctscrew a0 by means of which the body n may be fixed relatively to the carrying bars al and a2.

The carrying body b is actuated by means of a pair of toothed wheels b1, c1 from a shaft c supported in the'body 'n and actuated by a motor c2. The shaft d supported rotatable about the axis Y-Y in the carrying body b and ixable by a set-screw (Z0 relatively to the carrying body b, contains an index Z9 which indicates on a scale b2 ot the carrying body the position at any onetime of the shaftrelatively to the carrying body. The shaft d is screwed to two carriers d10 and du. The carrier (im carries four plates d2 and the car-` rierd11 live plates d2, Which'are perpendicular to the axis Y-Y and screwed together with the aid of bolts d3 and d3 respectively. The mechanisms for producing the motion of the parts requisite for the projection of the bodies of the solar system are assumed to be iixed between these plates, viz between the plates d2 of the carrier d10 the mechanisms for projecting the sun, the moon and Mercury and between the plates d2 of the carri er (Zu the mechanisms ,tor projecting Venus, Mars, J upiter and Saturn as indicated by the corresponding astronomical signs. For actu ating the lirst-namcd mechanisms a shait d4 is provided which is actuated by a motor d5 fixed on the carrier d10, while tor actuating the last-named mechanisms serves a shaft d4, actuated by a motor di lixcd on the carrier du. f

' Tofthe end plates 03 and cl2 two heini# spherical casings d1 and all respectively are screwed in such a way that the centre ot the spheres F and Gr respectively lies on the axis otrotation YY. On each of these two casincs there is lixed a 'iluralit of ifob l ,l jection apparatus cZ and Z7 respectively,

ot which the drawing only shows seven on each casing and cach of which serves for projecting a part of the fixed-star sky, in such a way that their axes intersect at the centre of the spheres F and G respectively. In each'or1 the said two casings there is disposed, common to the appertaining projection apparatus, a glow lamp cls` and d8 respectively, whose filaments enclose `the ap-y pertaining cent-res ofl the spheres F and G respectively. The projection apparatus ZT and (Zw are assumed to be distributed on the casings Zl and d1 in such a way that the whole northern and the southern ixcd-star sky can be projected, whereby the fixed starimagcs are so traced on the lantern slides oi these projection apparatus that the projection seems to take place from the' joint point of intersection E of the axes X-X, Y--Y and D-D.

In order to be able to project, on the one hand, a great circle Which'corresponds to the ecliptie and which results as intersecting line of the projection screen with the plane perpendicular to the axis Y-Y through E, and, on the other hand, a great circle which corresponds to the equator and which results as intersecting' line of the projection screen with the plane perpendicular to the axis X-Xjthrough E, six projection apparatus are provided;v Of these projection apparatus three p1, p2 and p3 are disposed on a plate b3, and further three 774, 795 and'pi on a plate b4, of the carrying body b in such a way that their optical axes intersect the axis X-X. Thereby on the lantern slides of these six pro1 jection apparatus images ot parts of both great circles are traced in such a way that during the projection the two circles are produced. without interruption. As the equator lies in a plane, which is perpendicular to the axis X-X, its position on the projection screen does not vary with rotations of the carrying body Z) in the body n.' Hence, with such rotations readily results the relative motion of the equator and the ecliptic correspending to the prccession of the points ot' intersection of these two planes relatively to the fixed stars (i. e. corresponding to the socalled procession of the equinoxes).

In order to be further able to project on the screen a. great circ-le correspondingvto 'that meridian, which results as intersecting line of' the screen with the plane, perpendicular to the axis D-D, through E, four projecn tion apparatus g1, (f, g3 and (It are fixed on a carrying bar al. As with the rotations of the carrying body about the axis X-X the projection apparat-us g1 and g2 are made inoperative by disposing in 'front of the 0b- -jectivcs of these projection apparatus parts participating in the rotation, there are fitted on the carrying bar a2 two further projection apparatus g1 and q2 in such a way that the lines projected by the apparatus g1 and (/2 coincide withthe lines projected by the apparatus g1 and g2.

c With the described suspension of the device by means of ropes the latter may be kept so thin that, even if only a single projection device be used for each body of the solar system, they do not impede the projection. ln the event of stronger constructionalparts it is advisable to use anarrangement as, e. g. illustrated in Fig.` 4,' which corresponds to the mechanism for projecting the sun shown in Fig. 2 of the copending application. With the "new arrangement there are screwed to the guide bar je, which is, on the one hand, displaceable in a cylindrical boring c1 of a guide body e and, on the other hand, supported rotatably byv means of a holder j about an axis N-N parallel to the axis Y-Y, two projection apparatus jl and jl in such a way that their optical axes are parallel to the axis of the guide bar je. Each of these two projection apparatus contains a glow lamp 7'2 and jz respectively, a condenser ,7'3 and js respectively, a diaphragm j" and v7'4 respectively, having a small aperture j and jm respectively, and an objective 7'5 and j respectively. Each of the two diaphragm apertures jo and jo lies outside the optical axis of the appertaining. projection apparatus in such a way that the images of the diaphragm apertures overlap each other on the'screen during the projection. The same efifect may also be attained by disposing the diaphragm apertures centrally with the optical axe's` of the projection apparatus and by screwing the latter to the guide .bar j in such a way that their optical axes intersect on the projection screen.v Ot the two projection apparatus one at most can always be covered by the carryingappliance.

Figs. 5 and 6 illustrate a carrying appliance which -may be used in the place ot the ropes employed in the deviceI according to Figs. I to 3. The carrying appliance consists of two iron frameworks each of which is composed ot two lattice carriers, formed by thin fiat bars '1' and reinforced relatively to each other. Each ofthe two frameworks carries one ot the two carrying bars al and a?. 'lhe bars 1' are substantially so disposed that in cach bar the plane, parallel to the two broadsides and bisecting the two narrow sides, containsthe vertical line through the point ot' intersection E of the axes X-QQ-Y-Y and D-D. Both frameworks rest upon a joint base-plate s. j

We claim:

l. Device for projet-ting the fixed stars,

contain-ing a carrying appliance, a. plurality f ot projection apparatus, each of wh1ch coniprises an optical system and an image of a part of the fixed stars, which optical systems and images are so disposed that the projected images adj oin each other corresponding to the natural aspect, two hollow bodies, onel group of the said projection apparatus being disposed at one and the other group being disposed at the other of these two hollow bodies, each hollow body containing a source ot light common to all vprojection apparatus appertaining to this body, the said two hollow bodies being rigidly connected together and rotatably supported on the said carrying appliance, and means for rotating the said two hollow bodies.

2. Device for projecting thev fixed stars,

containing a carrying appliance, a plurality of projection apparatus, each of which comprises an .optical system and an image of a part of the fixed stars, which optical systems and images are so disposed that the projected images adjoin each other corresponding to the natural aspect, two hollow bodies, one group of the said projection apparatus bei u g disposed at one and the other group being disposed at the other of these two hollow bodies, each hollow body containingl a source ot light common to all projection apparatus appertaiuing to this body, the said two hollow bodies being rigidly connected together and rotatably supported on a carrying body, this carrying body being rotatably supported on the said carrying appliance, the two axes of rotation intersecting each other between the two hollow bodies and forming with each other an angle of about 231/20, and means for rotating the said two hollow bodies relativelyT to the said carrying appliance.

3. Device for project-ing the fixed stars, containing a carrying appliance, a plurality of projection apparat-us, each of which comprises an optical system and an image of a part ot the fixed stars, which optical systems and images are so disposed that the projected images adjoin eachother corresponding to the. natural aspect, two hollow bodies, one group of the said'projection apparatus being disposed at one and the other group being disposed at the other of these two hollow bodies, each hollow body containing a source 'of light common to all projection apparatus apperlll() taining to this body, the said two hollow bodiesubeing rigidly connected together and rotatablysupported on a. carrying body, this carrying body being rotatably supported on another body, the two axes of rotation intersecting each other between the two hollow bodies and forming with each other .an angle of about 231/20, the said other bodybeing supported on the said carrying appliance rotat-l able about a horizontal axis lying in the plane determined by the two other axes of rotation andbeing perpendicular to theaxis about which the said carrying body is rotatable relatively to the said other body, and means for rotating the carrying body relatively to the said other body.

4'. Device according to claim 3, the said other body being supported on the said c-arrying appliance rotatable about the said horizontal axis through 360. l

5. In a device according to claim 1, the components of the carrying appliance being so narrow perpendicularto the direction of projection that an' objectionable darkening of the projected' images does not oecnrvif the carrying appliance comes within the reach of the rays.

6. Device for projecting'the fixed stars, containing a carrying ring, stay wires adapted to suspend 'the carrying ring, a plurality of projection apparatus, each ot which comprises an optical system. and an image of a part of the fixed stars, which optical systems and images are so disposed that the projected Aimages adjoin each other corresponding to -the natural aspect, two hollow bodies, one group of the said projection apparatus being disposed at one and the other group being disposed at the other of these twohollow bodies, each hollow body containing a source l of light common to all projection apparatus appertaining to this body, the said two hollow bodies being rigidly connected together and rotatably supported on the said carrying ring and means for rotating the said two hollow bodies.

'i'. Device for projecting stars, containing a plurality of projection devices, each of which comprises a casing, a pair-of projection apparatus, fitted within the casing rotatable each about an axis approximately perpendicular to the axis ot the apparatus, means for coupling each two apparat-us torming a pair -in such a way that the axes et these apparat-ns are inclined to each other at a small angle, and further 'con'iprising a gearing adapted to ilnpart to the said projection appara-tus rotations about their axes ot rotation. i

S. Device for projecting stars, containing a carrying appliance, a plurality of casings connected with each other, a plurality 'of prejection apparatus, each of which is fitted within one of the casings rotatable about an axis, approximately perpendicular to the axis paratus being disposed at one and the other group being disposed at the other ot these two hollow bodies, each hollow Ubody' containing a source of light common to all projection ap' paratus appertaining" to this body, the said two hollow bodies being rigidly connected together and rotatably supported on the said carrying appliance, means for connecting the said casings with the said two hollow bodies,

and other means for rotating the said two hollow bodies.

9. Device for projecting stars, containing a carrying appliance, two groups of casings connected with each other, a plurality of pro-. jection apparatus, each of which is tted within one of the casings rotatable about an axis approximately perpendicular to the axis ot the apparatus, a plurality of gearings, each of which is fitted within onev of the casings and adapted to impart to the pertaining p rojection apparatus rotations about the axis ot rotation of this apparatus, the device further containing a plurality of projection apparatus for projecting fixed stars, each of which comprises an optical system and an image of a part of the tixed stars, which optical .systerns and images are so disposed that the projected images adjoin each other corresponding to the` natural aspect, two hollow bodies, one group of the said projection apparatus being disposed at one and the other group being disposed at the other of these two hollow bodies, each hollow body containing a source of light common to all projection apparatus appertaining to this body, each of the said two groupsof casings being connected with one ofthe said two hollow bodies, the two groups ot casings and the two hollow bodies being rotatably supported on a body,

this body being supported on the said carrying appliance rotatable about a horizontal axis, the two axes ot rotation intersecting each other perpendicularly between the two hollow bodies, and means for rotating the said two hollow bodies relatively to the said body.

10. Device according to claim 9, the centre of gravity of the said body and of all parts fitted within it lying in the point of intersection of the said two axes.

11. Device for projecting stars, containing a carrying appliance, two groups of casings suA connected with each other, a plurality of projection apparatus, each of which is fitted within one of the casings rotatable about an axis` approximately vperpendicular to the axis of the apparatus, a plurality of gearings,

- image of a part of the fixed stars, which opticalsystems and images are so disposed that the projected images adjoin eachother corres nding to the natural aspect, two hollow bfodigs, one group of the said'projection'apparatus being. disposed at one and the other vgroup being disposed at the other of these two hollow bodies, each hollow body-containing a source of light common tov all projection apparatus appertaining to this body,

each of the said two groups of casings'being connected with one of the said two hollow bodies, the two groups of casings and the two hollow bodies bein rotatable on a carrying body, this carryingody being rotatably supported on another body, the two axes-of rotation intersecting each other between the two hollow bodies and forming with each other an angle of about 231/20, the said other body being supported on the said carrying appliance rotatable about a horizontal axis lying in the. plane determined by the two other axes of rotation and being perpendicular to the axis about which the said carrying body is rotatable relatively to the said other body, and means for rotating the said two hollow \bodies relatively to the. said body.

12. Device for projecting the fixedstars, containing a carrying appliance, a plurality of projection apparatus fitted on the saidl carrying appliance, and a source of light, the said projection apparatus being adapted to lreceive'light emanated'from the source of light, the device further containing other projection `apparatus adapted'to project circular lines.

. 13. In a device according to claim 2, a`

plurality of other projection apparatus, fixed on the said carrying body and adapted to project circular lines, each of which lines corresponds to a great circle of the fixed star sky perpendicular to one of the said two axes of rotation.

WALTER vrLLienR. 4 WALTHER BAUERSFELD. 

